1. Field of the Inventio:
The present invention relates to an apparatus for sticking a metal cord strip onto a tire component layer such as, for example, a rubber sheet layer held on a tire forming drum in a tire manufacturing machine.
1. Description of the Prior Art
A prior art apparatus for sticking a metal cord strip will now be explained with reference to FIGS. 6 and 7. In these figures reference character (a) designates a tire forming drum, character (b) designates guide plates, and (c) designates a plurality of vertical type guide rollers disposed in two rows on each guide plate (b), wherein the respective guide rollers (c) are mounted so as to be movable in the widthwise direction of the guide plate (b). In addition, reference character (d) designates width adjusting handles for adjusting the intervals in the widthwise direction of the above-mentioned two rows of guide rollers (c) a screw mechanism or the like, and character (e) designates metal cord strips, and when the metal cord strips (e) are stuck onto an outer circumferential surface of the tire forming drum (a), each of the metal cord strips (e) is fed towards the tire forming drum (a) as guided by the two rows of guide rollers (c) so that the metal cord strip (e) may be stuck onto the outer circumferential surface of a rubber sheet (a part of constituent elements of a tire, not shown) on the tire forming drum (a).
Of the metal cord strip sticking apparatus in the prior as shown in FIGS. 6 and 7, when the leading end inclined edge portion and the trailing end inclined edge portion of the metal cord strip (e) are stuck onto the outer circumferential surface of a rubber sheet on the tire forming drum (a), since a positioning device for restraining the lateral position of the metal cord strip (e) and a pressing device for pressing the leading end inclined edge portion and the trailing end inclined edge portion of the metal cord strip (e) onto the outer circumferential surface of the tire forming drum a are not provided and these operations must be carried out by workers, the sticking positions of the leading end inclined edge portion and the trailing end inclined edge portion of the metal cord strip (e) become inaccurate. Moreover, since human labor is necessary, and the sticking operation is not automated.
Furthermore, another example of an apparatus for sticking a metal cord strip in the prior art is shown in FIGS. 8 and 9. In these figures, reference character (b) designates guide plates, and character (c) designates a plurality of vertical type guide rollers disposed in two rows on each of the guide plates (b), wherein the respective guide rollers (c) are mounted so as to be movable in the widthwise direction of the guide plate (b). In addition, reference character (d) designates width adjusting handles for adjusting the intervals in the widthwise direction of the above-mentioned two rows of guide rollers (c) via screw mechanisms or the like, character (e) designates metal cord strips, character (f) designates a rubber sheet (a part of constituent elements of a tire) disposed on the backside of the above-mentioned guide plate (b), and reference character (g) designates press rollers movable in the direction of arrows, wherein when the metal cord strips (e) are stuck onto the outer circumferential surface of the tire forming drum (a), each of the metal cord strips (e) is fed towards the tire forming drum (a) as guided by the two rows of guide rollers (c). Subsequently press rollers (g) are moved from the positions shown by the dashed lines to the positions shown by the solid lines to bring the leading end inclined edge portion and the trailing end inclined edge portion of the metal cord strip (e) into press contact with the rubber sheet (f) to stick the former to the latter, and then the rubber sheet (f) is fed towards the tire building drum so that it may be wrapped around the outer circumferential surface of the tire building drum.
Of the metal cord strip sticking apparatus in the prior art as shown in FIGS. 8 and 9, when the leading end inclined edge portion and the trailing end inclined edge portion of the metal cord strip (e) are stuck onto the rubber sheet (f), since a positioning device for restraining the lateral position of the metal cord strip (e) is not provided and this operation is carried out by workers, the sticking positions of the leading end inclined edge portion and the trailing end inclined edge portion of the metal cord strip (e) become inaccurate.
In addition, a still further example of the metal cord strip sticking apparatus of the prior art is shown in FIGS. 10 and 11. In these figures, reference character (a) designates a tire forming drum, character (e) designates a metal cord strip, character (h) designates a first belt conveyor, character (i) designates a conveyor belt of the first belt conveyor (h), character (j) designates a drive roller for the conveyor belt (i), character (k) designates a plurality of magnets disposed right under the upper portion of the above-mentioned conveyor belt (i), character (l) designates a second belt conveyor which can travel back and forth, character (m) designates a conveyor belt of the second belt conveyor (l), characters (n) and (o) designate pulleys for the conveyor belt (m), character (p) designates a free roller conveyor disposed under the second belt conveyor (l), character (q) designates a positioning line upon conveyance of the metal cord strip which is an extension of one side edge of the upper portion of the conveyor belt (i) of the above-mentioned first belt conveyor (h), character (r) designates a plurality of guide rollers disposed along the positioning line (q), and character (s) designates a plurality of magnets disposed alternately with the respective guide rollers (r).
In operation, at first the metal cord strip (e) is placed on the upper portion of the conveyor belt (i) of the first belt conveyor (h), subsequently the second belt conveyor (l) advances until the front end portion of the second belt conveyor (l) is positioned right above the tire forming drum (a). Then the drive roller (j) for the first belt conveyor (h) and the tire forming drum (a) are driven, the movement of the same drive motor (j) is transmitted to the second belt conveyor (l) so that the second belt conveyor (l) is driven synchronously with the first belt conveyor (h), and the metal cord strip (e) on the first belt conveyor (h) is conveyed in the direction of arrow (A). At this time, the metal cord strip (e) is attracted by the respective magnets (k) and is thereby kept in tight contact with the conveyor belt (i). This metal cord strip (e) being conveyed in the direction of arrow (A) by the first belt conveyor (h) is soon transferred onto the free roller conveyor (p), it hence it leaves the magnetic field of the respective magnets (k) and enters the magnetic field of the respective magnets (s). While the metal cord strip (e) is attracted by the respective magnets (s), it comes into contact with the respective guide rollers (r), thus advancing along the positioning line (q) upon conveyance, and then leaving the magnetic field of the respective magnets (s) and entering the magnetic field of the respective magnets (t). Hence it floats up from the free roller conveyor (p) where attracted by the respective magnets (t), and comes into tight contact with the lower portion of the conveyor belt (m) of the second belt conveyor (l). Thereafter it is conveyed by the conveyor belt (m) of the second belt conveyor (l) and fed to a predetermined location of the rubber sheet mounted on the tire forming drum (a), and the leading end inclined edge portion of the metal cord strip (e) is stuck onto the above-mentioned rubber sheet. When the metal cord strip (e) has been wrapped by a predetermined length around the rotating tire forming drum (a), the first belt conveyor (h) and the tire forming drum (a) stop, subsequently the second belt conveyor (l) retreats, and so, a trailing end portion of the metal cord strip (e) which has been held in tight contact with the conveyor belt (m) of the second belt conveyor (l) peels off from the conveyor belt (m). At this time, a worker cuts the metal cord strip (e) into a predetermined length which corresponds to a residual wrapping length around the tire forming drum (a), subsequently the tire forming drum (a) is driven again, and the residual length of the metal cord strip (e) is wrapped around the tire forming drum (a), so that the trailing end inclined edge portion of the metal cord strip (e) can be stuck onto the above-described rubber sheet.
Of the metal cord strip sticking apparatus in the prior art as shown in FIGS. 10 and 11, since the respective magnets (s) and the respective guide rollers (r) are disposed only along one side edge of the metal cord strip (e) to be conveyed, that is, only along the positioning line (q) upon conveyance of the metal cord strip, the other side edge portion at the trailing end of the metal cord strip (e), i.e., a hatched portion (B) shown in FIG. 12 cannot be guided. Consequently when the leading end side portion of the metal cord strip (e) has been wrapped around the tire forming drum (a), it is necessary that a worker cut the metal cord strip (e) into a predetermined length which corresponds to a residual wrapping length around the tire forming drum (a), subsequently drive again the tire forming drum (a) to wrap the residual length of the metal cord strip (e) around the tire forming drum (a), and stick the trailing end inclined edge portion of the metal cord strip (e) onto the rubber sheet, and thus automation upon sticking of the metal cord strip (e) has not yet been achieved.
In addition, since positioning of the metal cord strip (e) cannot be achieved upon its conveyance unless the metal cord strip (e) is attracted by the respective magnets (s), a large frictional resistance arises between the metal cord strip (e) and the respective guide rollers (r), resulting in deformation of the metal cord strip (e).
Also, it is necessary to adjust and maintain the relative positioning of the first belt conveyor (h) with respect to the second belt conveyor (l) at a high precision, and consequently, there is a problem in that a lot of time and labor are necessitated for maintenance and control.